iOSOperating system · Cisco
CVE-2012-4658
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe ios-authproxy implementation in Cisco IOS before 15.1(1)SY3 allows remote attackers to cause a denial of service (webauth and HTTP service outage) via vectors that trigger incorrectly terminated HTTP sessions, aka Bug ID CSCtz99447.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe ios-authproxy (authentication proxy) implementation in Cisco IOS contains a denial of service vulnerability where incorrectly terminated HTTP sessions can cause the webauth and HTTP services to become unavailable. Remote attackers can exploit this by sending specially crafted HTTP requests that trigger improper session termination.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
iOSOperating system
<= 15.1\(1\)sy2= 15.1= 15.1\(1\)sy= 15.1\(1\)sy1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the device operating systemExecute 'show version' on the Cisco device and look for 'IOS' in the outputAffected if The device is not running Cisco IOS (for example, running IOS-XE, NX-OS, or ASA)
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Check the Cisco IOS versionExecute 'show version' and locate the version number (for example, 15.1(1)SY2). Compare your version against the affected ranges: <= 15.1(1)sy2, 15.1, 15.1(1)sy, 15.1(1)sy1Affected if The IOS version matches one of the affected versions listed
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Verify if webauth proxy feature is enabledExecute 'show running-config | include webauth' or 'show auth-proxy' to check for web authentication proxy configurationAffected if Web authentication proxy is configured and running on the device
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Confirm HTTP service is activeExecute 'show running-config | include ip http server' or check if the HTTP server is enabled for webauthAffected if HTTP server is enabled and accessible for authentication proxy purposes
A device is affected if it runs Cisco IOS version 15.1, 15.1(1)SY, 15.1(1)SY1, or 15.1(1)SY2 and has the webauth proxy and HTTP services enabled, making it vulnerable to denial of service from crafted HTTP requests.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade Cisco IOS to version 15.1(1)SY3 or later. If immediate upgrade is not feasible, consider disabling webauth proxy features or implementing network segmentation to limit exposure to untrusted networks.
Fix this in iOS
Scoped from the published advisory
- Consultation4.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,152.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-4658 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2012-4658 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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